Many patio or lounge chairs are presently marketed which consist of a back portion and a seat portion, these two portions being hingedly connected together in such a way that the back portion can assume any of a number of discrete angulated positions with respect to the horizontal. A particular form of hinging arrangement used in many conventional lounge chair constructions incorporates within the hinge itself a mechanism by which the back portion can be set to any of a number of discrete angles and will support the weight of the user while at that angle. The disclosure of the principal application Ser. No. 35,513 is concerned not with the hinge per se, but with the possibility of providing an arm rest structure on such a lounge chair, constructed so that arm members extending from the back portion will always remain horizontal or substantially so, regardless of the angle of angle of inclination of the back portion.
In any arm rest assembly for a lounge chair or similar structure (such as that set forth in the principal application Ser. No. 35,513), whenever the arm rest assembly is provided in the form an approximate parallelogram, there is always the possibility that, when the back part of the lounge chair or the like swings all the way backwardly to lie approximately parallel with the main part of the chair, the arm rest assembly can go through a dead center position, and become "locked" in that position so that it cannot be brought forwardly and upwardly again. In addition to this risk, depending upon the actual construction of the arm rest assembly, there can be a danger that the user's fingers will become trapped or snagged under the arm rest member, as and when the arm rest assembly approaches or goes through the dead center position. This risk will become clearer below, based on the discussion with reference to the drawings of this application.